dbSNP rs80338705: PMM2:p.His218Arg (chr16-8847737-A-G) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_000303.3(PMM2):c.653A>G(p.His218Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,350 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

PMM2
NM_000303.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.74

Variant links:

Genes affected

PMM2 (HGNC:9115): (phosphomannomutase 2) The protein encoded by this gene catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate, which is a precursor to GDP-mannose necessary for the synthesis of dolichol-P-oligosaccharides. Mutations in this gene have been shown to cause defects in glycoprotein biosynthesis, which manifests as carbohydrate-deficient glycoprotein syndrome type I. [provided by RefSeq, Jul 2008]

PMM2 links:

ENSG00000260350 (HGNC:):

ENSG00000260350 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a chain Phosphomannomutase 2 (size 244) in uniprot entity PMM2_HUMAN there are 79 pathogenic changes around while only 2 benign (98%) in NM_000303.3

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMM2	NM_000303.3 link	c.653A>G	p.His218Arg	missense_variant	Exon 8 of 8	ENST00000268261.9	NP_000294.1	O15305-1A0A0S2Z4J6Q59F02
PMM2	XM_047434215.1 link	c.404A>G	p.His135Arg	missense_variant	Exon 6 of 6		XP_047290171.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMM2	ENST00000268261.9 link	c.653A>G	p.His218Arg	missense_variant	Exon 8 of 8	1	NM_000303.3	ENSP00000268261.4		O15305-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251246

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135834

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000109

AC:

AN:

1461350

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727016

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000135

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Apr 29, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PMM2 c.653A>G (p.His218Arg) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251246 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.653A>G in individuals affected with Congenital Disorder Of Glycosylation Type 1a and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.39

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.24

CADD

Uncertain

DANN

Uncertain

0.98

DEOGEN2

Pathogenic

0.87

D;D;.

Eigen

Benign

0.17

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.91

D;D;D

M_CAP

Pathogenic

0.29

MetaRNN

Uncertain

0.69

D;D;D

MetaSVM

Pathogenic

0.89

MutationAssessor

Uncertain

2.5

.;M;.

PrimateAI

Benign

0.47

PROVEAN

Pathogenic

-5.3

D;D;D

REVEL

Pathogenic

0.77

Sift

Uncertain

0.0010

D;D;D

Sift4G

Uncertain

0.0050

D;D;D

Polyphen

0.014

.;B;.

Vest4

0.52

MutPred

0.80

.;Loss of sheet (P = 0.1158);.;

MVP

0.93

MPC

0.0076

ClinPred

0.96

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.94

gMVP

0.84

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over